Examining habitual brain circuitry in adolescents and young adults: From nomothetic to idiographic approaches
Open Access
- Author:
- Petrie, Daniel
- Graduate Program:
- Human Development and Family Studies
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- September 19, 2023
- Committee Members:
- Hobart Cleveland, Program Head/Chair
Sy-Miin Chow, Major Field Member
Stephen Wilson, Outside Unit & Field Member
Charles Geier, Chair & Dissertation Advisor
Zachary Fisher, Major Field Member - Keywords:
- habit
adolescence
neuroimaging
functional connectivity
OCD
Stress - Abstract:
- Despite the intuitive nature of habits, surprisingly little is known about habit formation and habitual behavior from a developmental cognitive neuroscience perspective, undermining our ability to characterize both normative brain development and, potentially, the emergence of psychopathology. In this dissertation, I use functional Magnetic Resonance Imaging (fMRI) to examine habits and habit formation during adolescence, using nomothetic and idiographic approaches. Nomothetic approaches find more generalizable or group-level information about the nature of habitual circuitry whereas idiographic approach can make targeted hypotheses about the individual. Three studies are presented that examine various aspects of habit in adolescents and young adults using these analytic perspectives. Study 1 takes a primarily nomothetic approach, examining associations among somatomotor-putamen connectivity, experienced/perceived stress, and their interaction on changes in obsessive-compulsive symptoms (OCS) in 5,170 adolescents from the Adolescent Brain Cognitive Development (ABCD) study. Results show that individuals with somatomotor-putamen resting state connectivity who experienced more stress than average reported more OCS. Conversely, individuals with greater somatomotor-putamen connectivity who experienced less stress reported fewer OCS. Findings from this study suggest that stress differentially influences the direction and magnitude of the relationship between somatomotor-putamen connectivity and OCS during adolescence. Study 2 takes a hybrid nomothetic/idiographic approach using Confirmatory Subgrouping Group Iterative Multiple Model Estimation (CS-GIMME) to better understand dynamics among prominent brain regions in the somatomotor-putamen network. Resting state fMRI data from 23 participants (11 adolescents, 12 adults) were used as input to CS-GIMME, capable of deriving functional connectivity networks at the group-, subgroup-, and individual levels. CS-GIMME recovered more short-distance connections within the somatomotor network in adolescents compared to adults, in line with past studies and suggesting that adolescents may have more hyperconnectivity in motor regions possibly reflective of more goal-directed vs. habitual motor action. Study 3 approaches habit neurocircuitry from an idiographic approach, using time-varying autoregressive (TV-AR) models fit within a generalized additive modeling framework. Changes in putamen BOLD activity were examined in 15 participants (9 adolescents, 6 adults) across three consecutive days of training on a classic habit task. Critically, I demonstrate how TV-AR models can be used to examine stationarity assumptions in BOLD data. Overall, TV-AR models fit the data well for most participants. However, out of the 45 scans analyzed, 4 (9%) were better characterized by a TV-AR model compared to a standard AR model using global fit indices. Within these 4 scans, the general trend was for the AR effect to increase across the scan as a result of training. This study demonstrates that stationarity assumptions may not hold even in simple experimental contexts, and that TV-AR models can identify changes in activation patterns that may be reflective of the transition to a different brain state. Overall, by combining approaches that span the nomothetic to idiographic analytic spectrum, this dissertation advances our understanding of the fundamental nature of habits and habit formation. Future work should build on these initial studies to better characterize neurodevelopment and highlight the importance of habit formation during adolescence and young adulthood.